Watch -makers  calipers



(No Model.)

J. M. IRMEN.

WATCH MAKBRS GALIPBRS. NCL/139,156. Patented 0013.28, 1890.

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To all whom it may concern.-

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UNITED STATES PATENT OFFICE.

JOHN M. IRMEN, OF ATLANTIQIOWA.

WATCH-MAKERS CALIPERS.

SPECIFICATION forming part of Letters Patent No. 439,156, dated October 28, 1890.

Application led March 10, 1890.

Beit known that I, JOHN M. IRMEN, a citizen of the UnitedStates, residing at the city of Atlantic, in the county of Cass and State of Iowa, have invented a new and useful Caliper, of which the followingis a specification.

My invention relates to improvements in that class of calipers which are used by watchmakers in properly adjusting balance-wheels and other wheels at true right angles to their axles; and the objects of my improvements are to facilitate the adjustment of wheels on their axles, so that they will project therefrom at true right angles to their axles; also, to facilitate the adjustment of the periphery of wheels, so that al1 part-s thereof will be equidistant from the axle; also, to facilitate the poising of wheels to determine if they balance on their axles. l attain these objects by the device illustrated in the accompanying drawings, in which- Figurel is a perspective view of the calipers, showing awheel secured within its jaws. Fig. 2 is a perspective view of a portion of the device, showing one of the jaws and parts contiguous thereto. Fig. 3 is a perspective view of the pivot of the caliper-sections. FigA is a longitudinal vertical sectional view, taken on the broken line .r az, Fig. 2, of one of the jaws and parts contiguous thereto.

Similar letters refer to similar parts throughout the several views.

The bent levers or sections C andD are piv otally connected by means of the pivot d', which passes snugly through the section C and loosely through the section D, and projects at each end beyond the sections. It is provided with the ledge e?, which rests on the upper side of the section D.

A is an arm pivoted to the upper side of the section C. It is composed of the section e and the bent section a2, pivotally connected by the rivet t'. The bent section a2 is provided with the projecting pin a,which serves as a handle for the arm A.

The face of each caliper-j aw is provided with several circular cavities g, of dierent dias shown in Fig. 4. Those ends of the caliper levers or sections C and D which have the jaws are provided with V-shaped notches d.

Serial No. 343,427. (No model.)

They also have grooves a cut on the Aupper and under surface of each near the face of the jaws, which form next to the face of the jaws sharp edges e. In those ends of the caliper-sections C and D which are not provided with the jaws are the circular cavities b.-

F. is an ordinarywatch balance-wheel secured within the caliper-jaws by having each end of its axle inserted in a cavity g. v

My device is operated as follows: A wheel is placed between the jaws of the calipers,with e'ach end of its axle inserted in a suitable cavity g. The arniAis then adj usted so that the inner end of its bent section a2 will come in contact with the side of the wheel at a point near its periphery, as shown in Fig. 1. The wheel is then revolved with the finger, and if the wheel projects from its axle at a true right angle to its axle the section a2 will remain at all times during the revolution of the wheel in contact with it; but if it is not at a true right angle the section a2 of the arm at some time during the revolution of the wheel will not be in contact with the wheel, and thus it can readily be determined in what direction the wheel should be bent or sprung in order to have it project at a true right angle from its axle, and if it is found not to project at a true right angle the ends of the axle are then removed from the cavities g and the axle inserted in the notches d and pressed firmly into the same. The jaws are then closed firmly against the wheel, and it is bent or sprung with the iin gers in the proper direction to cause it to project at a true right angle from its axle. To determine if all parts of the periphery of a wheel is equidistant from its axle, insert each end of the axle in a cavity g, as before explained, and adjust the arm A so that the inner end of the section a2 will come in contact with the periphery of the wheel. Then by revolving the wheel it can readily be determined by the position of the section a2 of the arm what portion, if any, of theperiphery should be removed to make all parts thereof equidistant from the axle. To determine if a wheel balances on its axle, the cali pers are held by the hand in a horizontal position, and the axle of the Wheel is placed IOO across the edges e in such a position that the wheel is suspended by its axle between the jaws Without coming in contact With them. Then if the Wheel does not balance on its axle the heaviest portion will gravitate downward and cause the Wheel to turn.

When the calipers are laid down on a table or bench, with awheel secured Within its jaws by means of having the ends of the axle inserted in the cavities g, the Wheel is prevented from coming in contact with the table or bench and thus bending its axle by means of the projected ends of the pivot cZ-,Which serve as supports for that portion of the calipers having the jaws.

Having described my invention,what I claim as new, and desire to secure by Letters Patent, is-

l. In watch makers truing-calipers, the combination of the bent levers or sections C and D, pivotally connected together, and each leverbeing provided with a notched jaw, substantially as described.

2. The combination, in Watch-makers truing-calipers, of the bent levers or sections C and D, pivotally connected together, and each lever being provided With a jaw having a V- shaped notch, substantially as set forth.

3. The combination, in Watch-makers truing-calipers, of the bent levers or sections C and D, pivotally connected together, and each lever being provided with a jaw having a sharp edge formed next to its face for the purpose of poising thereon watch-Wheels, substantially as set forth.

Li. The combination, in Watch-makers truing-calipers, of the bent levers or sections C and D, pivotally connected together, and each lever being provided with a notched jawhaving a sharp edge formed next to its face, substantially as set forth.

5. The bent lever or section D, provided at one of its ends with the notch CZ, the edge c, and cavity g, the bent lever or section C,piv otally connected by the pivot d to the section D, and being provided at onel of its ends with the notch CZ, the edge e, and cavity g, and the jointed arm A, pivotally connected to the lever or sect-ion C, all combined substantially as described.

JOHN M. IRMEN.

TWitnesses:

H. LANDMESSER, MAGGIE IRMEN. 

